Cornering lights

When I was young Mom & Dad had a 1977 Grand Prix that had cornering lights. I liked them. When John got his GL1500 it had cornering lights. I was jealous. I tried to figure out a way to add some to my GL1800, but got discouraged trying to decipher the GL1800 turn signal circuitry.

Recently a thread was posted on the GL1800riders forum about wanting some cornering lights. It piqued my interest again so I dug into the GL1800 schematics once more and finally figured out how the turn signals worked.

The trick to hooking up cornering lights is finding some way to trigger them that isn't flashing when the turn signals are on. On the GL1800 there are two continuous signals during the turn signal operation:

- The ground applied to the flasher relay by the turn signal cancel module.
- The front mirror marker light on the side that is turning is turned off to add distinction to the turn signal.
I designed a circuit to power cornering lights and posted it to the forum. 'Techdude2000' posted another version, and 'Waldo' posted a his design. Three different designs that do the same thing. It was nice to have choices. I liked Waldo's best. It was simpler to implement and the cornering light relays were only on when needed. I bought some cheap lights at Walmart to use. They were the smallest they had.

First thing to do was find the wire to the mirror marker light as it will do the triggering. The one for the left side is orange/white and is available two the harness to the mirror, or the big harness under the left storage pocket. I chose to tap off the big harness since it's more tucked away.

This wire is on with the key...

...but off when the turn signal is on.

Trigger wire to the relay is soldered.

Mirror marker light wire on the right side.

I have a relay that provides 'key-on' power... a fuse block in the trunk. I got power for the cornering light relays here (green wire). You need to use 'key-on' power otherwise the cornering lights will come on when you shut off the bike.

Each of my air snorkels have terminal strips mounted on them to make various connections to. I made my power/relay/light connections here (blue arrow). The power wire (green) connects here and continues to the other side. The relay is tucked away forward (green arrow). The trigger wire connection can be seen at the purple arrow.

Here are the experimental lights in the experimental location.

It's currently winter, so it'll be awhile before I can test these out. If the concept works I'll find some smaller/thinner lights. I think the air scoops in front of the radiators would be a great place for cornering lights.

Update - We installed cornering lights on John's Goldwing. It was much easier to access the trigger wires by removing the mirror glass and tapping into the wiring there and feeding the wires down.

Usage update - The cornering lights work great. They do a good job of lighting upcoming turns. They are also great for lane changing. John and I still use the cheap lights we got at Walmart.

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